docs: remove decorative separator comments

Strip box-drawing (──) section dividers and ===/banner headers — visual
noise with no information. Where a divider label carried a non-obvious
why (VirtualList owns scrolling; mobile footer is md:hidden because header
stats take over) it is kept as a plain one-line comment; pure restatements
of the markup (Header bar, Red hover line, Bottom: fixed controls) are
dropped. Single comment style, no fluff.

src/entities/Font/ui/FontSampler/FontSampler.svelte

@@ -102,7 +102,6 @@ const stats = $derived([
     "
     style:font-weight={typography.weight}
 >
-    <!-- ── Header bar ─────────────────────────────────────────────────── -->
     <div
         class="
             flex items-center justify-between
@@ -163,7 +162,6 @@ const stats = $derived([
         </div>
     </div>
 
-    <!-- ── Main content area ──────────────────────────────────────────── -->
     <div class="flex-1 p-4 sm:p-5 md:p-8 flex items-center overflow-hidden bg-paper dark:bg-dark-card relative z-10">
         <FontApplicator {font} {status}>
             <ContentEditable
@@ -175,7 +173,7 @@ const stats = $derived([
         </FontApplicator>
     </div>
 
-    <!-- ── Mobile stats footer (md:hidden — header stats take over above) -->
+    <!-- Mobile stats footer; md:hidden because the header stats take over above -->
     <div class="md:hidden px-4 sm:px-5 py-1.5 sm:py-2 border-t border-subtle flex gap-2 sm:gap-4 bg-paper dark:bg-dark-card mt-auto">
         {#each stats as stat, i}
             <Footnote class="text-5xs sm:text-4xs tracking-wider {i === 0 ? 'ml-auto' : ''}">
@@ -187,7 +185,6 @@ const stats = $derived([
         {/each}
     </div>
 
-    <!-- ── Red hover line ─────────────────────────────────────────────── -->
     <div
         class="
             absolute bottom-0 left-0 right-0